Not surprisingly, the alert caused widespread panic, coming at a time of heightened tensions with North Korea. Security experts called it a frightening warning of how a technical error could set off an unintended conflict.

Since the dawn of the nuclear age, there have been no shortage of erroneous alarms. We revisited a few.

From left, Ryan Locke, Robyn Sinclair and Terron Wood. Each said he had experienced sexual harassment during his time modeling.CreditRyan Young for The New York Times; Lam Yik Fei for The New York Times; Amanda Lucier for The New York Times

• A frenzy over cryptocurrencies has sent their value soaring and investors scrambling.

But the leading player, Bitcoin, was rattled last week by word that South Korea is preparing a ban on trading in virtual currencies. But it isn’t clear whether, or how quickly, it will follow through.

And we went inside the newly megarich cryptocurrency community and found a tightknit group of friends — developers, libertarians, Redditors and cypherpunks — who talk about decentralizing power and wealth, and changing the world order. (They also remember who laughed at them.)

In the News

• A passenger plane skidded off a runway in Turkey, ending up stuck on a steep slope feet from the Black Sea. No one was hurt. [The New York Times]

• In Chile, firebombs exploded outside three churches, apparently to highlight the plight of an indigenous group and the issue of sex abuse before Pope Francis’ visit. [The New York Times]

• President Rodrigo Duterte of the Philippines rejected calls from his allies to extend his six-year term and to cancel elections next year. [VOA]

• A volcano eruption forced the evacuation of 1,500 people from an island off the northern coast of Papua New Guinea. [Reuters]

• Prime Minister Shinzo Abe of Japan could miss the opening ceremony of the Winter Olympics as tensions with South Korea flared over World War II-era sex slaves. [The New York Times]

• A 7.1-magnitude earthquake off Peru’s coast early Sunday killed at least one person and injured dozens. [AP]

• The police in China used explosives and heavy machinery to destroy a Christian megachurch in part of what critics called a national effort to control the country’s spiritual life. [The New York Times]

• Prime Minister Benjamin Netanyahu arrived in New Delhi for the first visit by an Israeli leader to India in 15 years. [Indian Express]

The distinctive design came from the shape of the first proposed site, which was hemmed in by streets on five sides. When President Franklin Roosevelt decided on a different location, the shape stayed, but the sides were made even.

The first architectural reviews were not glowing, but they improved over time.